Could use some slight help with the blocks/wrappers.

I've got an image I want to pop up as a background on our website.



I've got it on there using firebug so only I can view it and looks great!



Problem is you cant see any of the block writing. The background color is dark and so is all the writing on the whole page.

.

I know there is a way to do this, just cant pin exactly how to do it.

I would like to make the block content themselves a white or gray. So then I could see the writing on the webpage and So that the block will look like its floating on the background.



Can someone just point me in the right direction of doing this?